Introduction to RTCA Special Committee 206 and Standards ......Update the MASPS 6 presents comments...

Introduction to RTCA Special Committee 206 and Standards Development for Aeronautical

Information and Meteorological Data Link Services Systems

Summer 2016 FPAW MeetingStephen Darr, Dynamic Aerospace, Inc.

Purpose and Outline (formal)

Purpose: Provide status on development and approval of standards for Aeronautical Information Services (AIS) and Meteorological (MET) Information Data Link Services by RTCA

Outline• SC-206 Overview

• Minimum Aviation System Performance Standards (MASPS) Purpose and Scope

• MASPS Development and Status

• Requirements and Recommendations: System, Communications Mode, Interoperability, and Verification

• Aircraft-based Observations Requirements and Recommendations

NOTE: Charts in this format won’t be briefed

03 August 2016 MASPS is in FINAL REVIEW DRAFT status 2

Purpose and Outline (informal)

• Purpose: To let you know that a standard that includes requirements for near real time aircraft-based observation systems is nearing publication by RTCA

• Encourage you to go through the formal portion of the briefing (only informal charts will be briefed)

• Outline• What’s a MASPS anyway?• What is the current status of the MASPS and when will it be

published?• Weather Surveillance

• What is WxS?• What parameters will be reported?

• By whom? Where? When? Why? How?


SC-206 OVERVIEW

4

SC-206 Overview

LeadershipCo-Chairs: Allan Hart (Honeywell) & Capt. Rocky Stone (United Airlines)

Designated Federal Official: Eldridge Frazier (ANG-C61 Aviation Research Branch)

Secretary: Tom Evans (NASA)

SG1: (MET/Wake/ATM) Ed Johnson (FAA) & Clark Lunsford (MITRE)

SG4: (EDR MOPS) Tammy Farrar (ANG-C64) & Bill Watts (Delta Airlines)

SG5: (FIS-B UAT MOPS) Paul Freeman (Harris Corp) & John Ferrara (GA Pilot Consultant)

SG6: (DL Services MASPS) Bill Carson (MITRE) & Stephen Darr (Dynamic Aerospace)

SG7: (Guidance for DL Forecast & Real-Time Wind) Ernie Dash (AvMet) & Michael McPartland (MITLL)

Active Organizations (20)Air Line Pilots Association

AvMet Applications

Boeing

Delta Air Lines, Inc.

Dynamic Aerospace, Inc.

Federal Aviation Administration

Foreflight

Garmin

GE Aviation

Harris Corporation

Honeywell International, Inc.

MITRE

MIT Lincoln Laboratory

NASA

National Air Traffic Controllers Association

NAV CANADA

Panasonic Avionics Corporation

U.S. Air Force

United Airlines, Inc.

World Meteorological Organization

Established in 2005 to develop standards for

Aeronautical Information Services (AIS) & Meteorological Data Link Services


Terms of Reference: MASPS

Develop the MASPS for AIS and MET Data Link Services• Define system requirements that increase flight safety and

efficiency through the transmission of meteorological and aircraft parameters to enable wake vortex, ATM, and weather applications as described in RTCA DO-339.

• Define system requirements for downlink of aircraft derived data to support various ground based wake vortex, ATM, and weather applications, such as enhancements to Wake Turbulence Mitigation systems.

• Define system requirements for crosslink of aircraft-derived meteorological data supporting wake vortex, ATM, and weather applications, such as those required for Flight deck-based Interval Management (FIM).

• Define system requirements that increase flight safety and efficiency through the uplink of:

• AIS information• MET information (e.g. turbulence information)

603 August 2016 MASPS is in FINAL REVIEW DRAFT status

MINIMUM AVIATION SYSTEM

PERFORMANCE STANDARDS

(MASPS) PURPOSE AND SCOPE

7

What’s a MASPS anyway?

• Minimum Aviation System Performance Standards (MASPS) describe the operation of a system/ application, its performance requirements, interoperability needs, and procedures for verifying performance early in its development.

• MASPS specify fairly detailed performance requirements to support the prototyping, demonstration, and further development of the application/ system.

• MASPS are not MOPS• Minimum Operation Performance Standards (MOPS) provide

requirements for the application of pertinent technology to fulfill user needs, e.g. electronic systems and equipment that support aviation


MASPS Purpose & Scope

Provides minimum standards for AI & MET Data Link Services systems

• Defines system requirements based on an intended use of information transfer

Requirements provide adequate assurance that AI and MET Data Link Services systems will function in an acceptable manner

• Compliance is recommended as one means of assuring that systems perform satisfactorily under all conditions normally encountered in aeronautical operations

Requirements are allocated at the system level, with some allocated to specific functions (transmit, channel, receive)

• Requirements are also allocated to the communication mode (Broadcast, Publish-Subscribe, and Request-Reply)

• Requirements are provided for Weather Surveillance Service systems based on an intended use of automatically and continuously compiling meteorological observations onboard aircraft and transferring that information in near real time to the ground

Builds on previously published RTCA, EUROCAE, and other standards developed to support future ATM capabilities.

• Describes processes and protocols for wireless communications which may use celestial or terrestrial links

• Draws on parallels with ARINC Specification 620 (Data Link Ground System Standard and Interface Specification), and ARINC Specification 622 (ATS Data Link Applications Over ACARS Air-Ground Network).


Beyond Scope

Because of the diversity of Data Link Services systems that could be developed, the MASPS does not attempt to define requirements for:• Specific data link services, other than the Weather

Surveillance Service;

• Technical services defined by organizations such as Open Geospatial Consortium; e.g., Web Feature Services;

• Information quality, e.g., accuracy of AI or MET data;

• Human factors considerations; message protocols; security; or,

• External aircraft systems’ use of AI or MET information

Certification and operational approvals must be granted by approval authorities, who may use the contents of the MASPS in whole or in part• Use cases provide context for system safety analysis by

industry


MASPS DEVELOPMENT AND

STATUS

11

MASPS Development Approach

12

Due to the TORs calling out DO-339 systems and the recommendations from DO-360, Section 3.3 provides

requirements for transmission of meteorological and aircraft parameters to enable wake vortex, ATM, and

weather applications via the Weather Surveillance (WxS) Service systems.

SAA

Use

Case

ETS

Use

Case

WxS

Use

Case

OPA Assessment > Performance ReqsOSA Assessment > Safety Reqs



Common Requirements

Analysis

System Reqs24 Op Reqs2 Op Recs(Sec 3.2.1)

Comm Mode Reqs12 Op Reqs(Sec 3.2.2)

Interoperability20 Reqs5 Recs(Sec 4.3)

DO-339 &

DO-360

Data Acquisition Requirements- 6 Perf ReqsObservation Compilation Requirements- 24 Perf ReqsWxS Message Type and Transmittal Requirements- 16 Perf ReqsWxS Configuration Control Requirements- 9 Perf Reqs

?

Sec 3.3

Appendix AAppendices B & C


OSA & OPA

Approach

Example OSA results

Example OPA results

Departs from DO-324 approach by

performing a qualitative vs.

quantitative assessment

IMMs & EMMs do not have

associated probabilities

DO-264 allows for this approach

with qualitative approach done

previously

Guidance for converting qualitative

results to quantitative probabilities

(e.g., DO-350)

Deviations from “normal”

approaches are noted

E.g., Fault Trees are presented in

table format

Assessing Single and Multiple

aircraft simultaneously

Effects of Detecting hazards or not

and equivalence of OHs

OH-SAA-01 Unavailable SAA Notification

Airspace with ATC Communications Airspace without ATC Communications

Single Multiple Single Multiple

Effect on Detected Undetected Detected Undetected Detected Undetected Detected Undetected

Operations 5 4 5 4 4 3 4 3

Occupants 5 5 5 5 5 5 5 5

Aircrew 4 4 4 4 4 3 4 3

ATS 5 5 5 5 5 4 5 4

SC = 5 4 5 4 4 3 4 3

Requirements SAA ETS WxS

Timing 180 TTmax / 120 TT95

sec

60 sec (update interval) 60 sec (update interval)

Continuity 0.999 0.999 0.999

Availability of

Service

0.999 0.999 0.999

Integrity 0.999 with comm

0.99999 without comm

0.999 0.999


OPA/OSA Info Flow & Requirements Development

Use Case OSA

OPARTCA

Standards Guidance

RTCA/EUROCAE and Other Standards and

Documents

Performance Requirements

Timing, ContinuityAvailability, & Integrity

UsedDO-264

guidelines

SAA Use Case

ETS Use Case

For SAA System

For ETS System

For WxS System

WxS Use Case

The requirements defined in Appendices B & C apply to specific use cases

Safety Requirements

Operational Hazards

Environmental Condition

External Mitigation Means

Internal Mitigation Means

Basic Causes

Severity Class


Use Cases

AIS Special Activity Airspace Notification (uplink)

• Notifies flight crews and associated AOC/FOC of unplanned for or unexpected activation/deactivation of Special Activity Airspace that necessitates or provides opportunity for changing route

• System description identifies a DMS (GDLPF/tDLPF), an ISP (DLSPF/cDLPF) & a CMU (ODLPF/rDLPF)

MET Eddy Dissipation Rate Turbulence (crosslink)

• Provides for in-flight reporting and receipt of aircraft-derived Eddy Dissipation Rate turbulence information in real time.

• System description identifies ADS-B out (ODLPF/tDLPF) and ADS-B in (ODLPF/rDLPF)

MET Weather Surveillance (downlink)

• Provides aircraft-derived, geographically and temporally referenced MET information to ground-based repositories

• System described as ADS-Wx system


What is the current status of the MASPS and when will it be published?


MASPS Development Objectives & Status

Section Oct 2015 Dec 2015 Mar 2016 Jun 2016 Sep 2016 Dec 2016

MASPS DevelopmentFRAC

Release

F

R

A

C

R

e

s

o

l

u

t

i

o

n

M

A

S

P

S

P

M

C

A

p

p

r

o

v

a

l

1 Red Blue Green Black



4 Red Red Blue Black

5 Red Red Blue Black

A Red Green Black Black

B Red Green Black Black

C Red Green Black Black

17

Done / N/A

MatureNeeds RevisionNeeds Input (<70%)


MASPS FRAC Timeline

18

PlenaryFRAC

Release6/17/2016

PlenaryFRAC

Resolution9/16/2016

FRAC duration30 days

6/27/16 – 7/29/16

PMC12/15/16

45-60 days

SG-6 Edit

- SG-6 finalized the MASPS and presented it to SC-206

- SC-206 approved for FRAC Release

- The document will be sent to the PD

- Reviewers will have FRAC period to provide their comments and suggest revisions

- Comments will be posted on Workspace for transparency

- SG-6 will work the comments

- Classify by category and work to resolve comments

- Update the MASPS

- SG-6 presents comments and resolutions to SC-206

- Committee will agree on the comment resolution and approve document for release to PMC

Final – clean document

delivered to RTCA(NLT 10/10/16)

- SG-6 update the document as needed

- PD will send a notification email with FRAC instructions

- PD will post the document on Workspace

Summer FPAW


AI AND MET DATA LINK SERVICES SYSTEM

REQUIREMENTS AND RECOMMENDATIONS

All requirements are in draft status, with comments received during

Final Review and Comment period being resolved at this time.

19

AI & MET Data Link Services System

System description eliminates physical location references and implied transmit receive functions and directionality from those presented in earlier SC-206 documents• RTCA DO-340 and DO-349 used GDLPF, ODLPF, and DLSPF definitions

originally established by the FAA’s Aircraft Access to SWIM (AAtS) program

The decision to change the functional descriptions in the diagram and the body of the document was made as part of the requirements development after the Use Cases and associated OSA and OPA analyses (Appendices A-C) were developed

20

cDLPF

rDLPFtDLPF

B

1

2

A C

3

D

4

AIS / METInformation

Output

AIS / METInformationInput

DLPF= Data Link Processing Functiont = transmitting

c = channelr = receiving

I O

Out of scope element

System Function

Network Interface

Application Interface # #

# #

System Interface ɑ #


Requirements & RecommendationsMASPS Sections 3 and 4 establish minimum requirements that designers, manufacturers, installers, service providers, and users of AI and MET Data Link Services’ systems should evaluate to determine their appropriateness, when developing, deploying and using systems

The requirements were derived from an assessment of use case requirements (Appendices B and C) for commonality and are presented within the hierarchy of System, Communications Mode and Interoperability

• Specific performance and safety numerical requirements are dependent on the specific Data Link Service System

• Therefore, no numerically-based requirements are defined outside the use case specific appendices

• Applicants will have to interpret and determine specific service system requirements if authorities invoke the MASPS

Section 3.3: Real Time, Aircraft-based Meteorological Observation Service System

• Per the TORs, a specific section on the requirements for implementing real time, aircraft-derived, MET observation service systems was added in support of RTCA DO-339 and in response to RTCA DO-360 recommendations

• Aircraft-based Observation system requirements are defined only for the onboard elements of such a service and include requirements for:

• Data acquisition range and resolution

• Observation compilation ranges and resolutions

• Message type and transmittal

• Configuration control


System Requirements & Recommendations

OR-system-01 The system shall be capable of operation in mixed equipage environments.

OR-system-02 The system shall not diminish the effectiveness of ATC safety services.

OR-system-03 The system shall not diminish the effectiveness of AOC support of safety services.

OR-system-04 The loss of the use of the system shall not create unacceptable safety risk.

OR-system-05 The system architecture shall support the intended uses.

OR-system-06 The Communications Effective Range of the system shall support the intended uses.

OR-system-07 The system shall check that the output values are consistent with the input values received at each interface.

OR-system-08 Procedures for system operations shall be published.

OR-system-09 Training material for system operations shall be published.

OR-system-10 The system shall have a means of determining that external sources are no longer available.

OR-system-11 The system shall meet minimum integrity requirements.

OR-system-12 The system shall meet minimum continuity requirements.

OR-system-13 The system shall meet minimum availability of service requirements.

OR-system-14 The system shall provide functionality that ensures outputs are consistent with inputs received

OR-system-15 The system shall provide an indication of failure(s) to properly deliver data across its communications infrastructure.

OR-system-16 The system shall provide an indication when required external inputs are no longer available.

OR-system-17 The system shall monitor integrity.

OR-system-18 The system shall monitor continuity.

OR-system-19 The system shall monitor availability of service.

OR-system-20 The system shall provide a means to indicate that integrity requirements are not met.

OR-system-21 The system shall provide a means to indicate that continuity requirements are not met.

OR-system-22 The system shall provide a means to indicate that availability of service requirements are not met.

OR-system-23 The system shall provide a means to indicate to external recipient(s) when data is no longer available.

OR-system-24 The system shall maintain time synchronization to within one second with UTC

ORec-system-01 The cDLPF should implement an integrity check that ensures proper delivery of data across its communications infrastructure, or provides notification upon failure.

ORec-system-02 The cDLPF should implement a means to confirm messages are received from the tDLPF.


Communications Mode RequirementsBroadcast Mode Requirements

• OR-commB-01 Broadcast mode communications shall be one-way.

• OR-commB-02 Broadcast mode communications shall be unaddressed.

• OR-commB-03 Broadcast mode communications shall be unacknowledged.

• OR-commB-04 In Broadcast mode, the system shall meet update interval requirements.

Request-Reply Mode Requirements

• OR-commRR-01 In Request-Reply mode, for addressed messages, the system shall meet maximum transaction time requirements.

• OR-commRR-02 In Request-Reply mode, for addressed messages, the system shall meet 95% transaction time requirements.

• OR-commRR-03 In Request-Reply mode, for addressed messages, the system shall meet minimum availability of use requirements.

• OR-commRR-04 In Request-Reply mode, unaddressed messages shall be unacknowledged.

Publish-Subscribe Mode Requirements

• OR-commPS-01 In Publish-Subscribe mode, for addressed messages, the system shall meet maximum transaction time requirements.

• OR-commPS-02 In Publish-Subscribe mode, for addressed messages, the system shall meet 95% transaction time requirements.

• OR-commPS-03 In Publish-Subscribe mode, unaddressed messages shall be unacknowledged.

• OR-commPS-04 In Publish-Subscribe mode, for addressed messages, the system shall meet minimum availability of use requirements.


System & External Interface Requirements

The following requirements apply at the system level:

IR-system-01 The tDLPF shall be able to communicate with the rDLPF via one or more cDLPF

IR-system-02 The system shall be capable of operation in environments in which not all aircraft are AI and MET Data Link Services system equipped

IR-system-03 The system shall provide a means to indicate to external recipient(s) when data is no longer available

IR-system-04 The system shall have a means of determining that external sources are no longer available

IR-system-05 The system shall provide a means to indicate when required external inputs are no longer available

IR-system-06 The system shall check that the outputs at interface 4 are consistent with the inputs at interface 1

IR-system-07 The system shall provide a means to indicate to external entities when the outputs at interface 4 are inconsistent with the inputs at interface 1

External Interoperability Requirements: Interface I -> 1:

IR-external-01 The tDLPF shall be able to communicate with external information source(s)

IR-external-02 The tDLPF shall be able to receive information from one or more external input(s)

IR-external-03 The tDLPF shall be able to monitor the interface(s) with external information source(s)

IR-external-04 The tDLPF shall provide a means to indicate when external inputs are no longer available

External Interoperability Requirements: Interface 4 -> O:

IR-external-05 The rDLPF shall be able to communicate with one or more external information output entities

IR-external-06 The rDLPF shall be able to send information to one or more external output(s)

IR-external-07 The rDLPF shall be able to monitor the interface(s) with one or more external information output entities


Internal Interface Requirements

Internal Interoperability Requirements: Interface 2 -> 3:

IR-internal-01 The tDLPF shall incorporate an integrity check.

IR-internal-02 The rDLPF shall incorporate an integrity check.

IRec-internal-01: The tDLPF should be able to use multiple communication channels

Internal Interoperability Requirements: Interface A -> B:

IR-internal-03 The tDLPF shall be able to communicate with one or more cDLPF

IR-internal-04 The tDLPF shall be able to exchange messages with one or more cDLPF

IRec-internal-02: The tDLPF should be able to support simultaneous connections with multiple communications channels

IRec-internal-03: The tDLPF should be able to encode messages in accordance with generally accepted international standards

Internal Interoperability Requirements: Interface C -> D:

IR-internal-05 The rDLPF shall be able to communicate with one or more cDLPF

IR-internal-06 The rDLPF shall be able to receive data from one or more cDLPF

IRec-internal-04 The rDLPF should be able to support simultaneous connections with multiple communications channels

IRec-internal-05 The rDLPF should be able to decode messages in accordance with generally accepted international standards


Verification Guidance

The purpose of this section is to provide guidance to stakeholders relating performance verification and system tests to performance requirements.

• This guidance is not intended to establish procedural detail for how to conduct verification testing for each requirement.

A plan, or equivalent formalization of verification activities, should be developed to ensure proper traceability and compliance with performance requirements. It should address the following points:

• Who: Clear identification of the individuals and/or organizations involved in the activities and the roles and responsibilities of each team member should be defined;

• What: The objectives of verification should be defined, establishing acceptance criteria and methods for verification of the requirements; and,

• How: The plan should define the activities and specify the required documentation necessary to demonstrate compliance with all requirements.

Process Methodology

• Any combination of the following methods can support system performance verification:

• Demonstration• Examination• Analysis• Test


AIRCRAFT-BASED OBSERVATION (AbO)

REQUIREMENTS AND RECOMMENDATIONS

All requirements are in FINAL REVIEW DRAFT status, with

comments received during the Final Review and Comment period

being resolved.

27

What is Weather Surveillance (WxS)?• The Weather Surveillance (WxS) use case proposes

the periodic, immediate broadcast of aircraft-based observations, extending AMDAR and similar aircraft-based observation system requirements to near real time reporting.

• The requirements for WxS onboard systems are derived from the WxS use case, RTCA DO-339, and requirements and recommendations found in ICAO Annex 3 and in the AMDAR Onboard Software Functional Requirements Specification (AOSFRS). They are biased toward extending existing requirements rather than obviating them.


What parameters will be reported?Mandatory Parameters (if participating and equipped)• Observation reference

• Lat/Long, Pressure Altitude• Date, Time

• Meteorological• Static Pressure and

Temperature• Wind Direction and Speed

(with quality flag)• Eddy Dissipation Rate (if

equipped)• Water Vapor (if equipped)• Windshear (if equipped)

Recommended and Optional Parameters

• Aircraft Status• Size (wingspan, gross

weight, type/emitter type)

• Configuration (flaps, airspeed, heading)

• Optional• Icing & Anti-ice Status

• Departure & Arrival Airports

• GNSS Altitude


By whom? Where? When? Why? How?• By whom?

• Voluntarily equipped aircraft from individual GA thru commercial fleet operators

• Where?• Wherever equipped aircraft are operating

• When?• From Out thru In• Every 60 seconds for low-rate reporting• Every 10 seconds for high-rate reporting

• Why?• To characterize the atmosphere in support of wake, weather

forecasting, and ATM applications, and others TBD

• How?• Automatically, accessing best onboard sources, to repositories

unspecified, via data link


AbO Data Acquisition Requirements

PR-AbO-01 WxS onboard system data acquisition shall be accomplished by integrating data sources, or interoperating with external aircraft systems, to ensure compliance with the sensing and/or derivation, compilation, and transmittal requirements for reported parameters.

PR-AbO-02 WxS systems shall use the last valid sample for all input data when reporting or deriving observation parameters.

PR-AbO-03 WxS systems shall only use input data that is validated using applicable avionics standards.

PR-AbO-04 WxS systems shall only use input data that passes out of range checks for the parameter ranges specified in the Input Data Range and Resolution table.

PR-AbO-05 WxS systems shall only use valid input data for calculations.

PR-AbO-06 WxS systems shall only use valid input data for derivation of parameters.


WxS Input Data Ranges and Resolutions

Description UnitResol

utionRange

Preferred

Acquisitio

n Rate

Aircraft ID Character N/A N/A N/A

Air/Ground Switch or

Weight on Wheels

Discrete N/A N/A 1 Hz

Computed Airspeed Knots 1 0 through

800

1 Hz

Date Day Day of Month 1 0 through

31

1 Hz

UTC Hours Hours 1 00 through

23

1 Hz

UTC Minutes Minutes 1 00 through

59

1 Hz

UTC Seconds Seconds 1 00 through

59

1 Hz

Latitude Degrees,

Minutes,

Seconds

1

Secon

d

90 S

through 90

N

1 Hz

Longitude Degrees,

Minutes,

Seconds

1

Secon

d

180 E to

180 W

1 Hz

Pressure Altitude in

ICAO Standard

Atmosphere

Feet above

Mean Sea Level

1 -1000

through

50000

1 Hz

Static Air Temperature Degrees Celsius 0.1 -99.9

through

+99.9

1 Hz

Static Pressure (Note 1) Hectopascals

(millibars)

1 900

through

1050

1 Hz

Wind Direction (True) Degrees 1 0 through

359

1 Hz

Wind Speed Knots 1 0 through

800

1 Hz

Description UnitResoluti

onRange

Preferred

Acquisition

Rate

Roll Angle Degrees 1 -180 to 180 1 Hz

Pitch Angle Degrees 1 -90 through

90

1 Hz

Departure Station Character N/A N/A N/A

Destination Station Character N/A N/A N/A

Vertical Speed (Note 2) Feet per Minute 1 -2000

through 2000

1 Hz

Gross Weight (Note 3) Kilogram 1 N/A 1 Hz

Vertical Acceleration G 0.001 -3 through

+6

8 Hz

Water Vapor Data Note 4 1 Hz

Icing Status Discrete N/A N/A 1 Hz

Anti-Ice Discrete N/A N/A 1 Hz

Flap Position Degrees 1 0 through 50 1 Hz

Gear Position (Up/Down) Discrete N/A N/A 1 Hz

GNSS Altitude Feet 1 -1000

through

50000

1 Hz

Groundspeed Knots 1 0 through

800

1 Hz

Track (True) Degrees True 0.1 0.0 through

359.9

1 Hz

Heading (True) Degrees (True) 0.1 0.0 through

359.9

1 Hz

True Airspeed Knots 1 0 through

800

1 Hz

Aircraft Type (ICAO or

Emmitter Category)

Character N/A N/A N/A

Windshear Airspeed

Change (Note 5)

Knots 1 -40 through

40

1 Hz

Wingspan Feet 0.1 0 through

400

N/A


AbO Observation Compilation Requirements

and RecommendationsPR-AbO-07 Reported parameter values shall be obtained or derived from the highest frequency instantaneous

sample available, closest to the observation time, and in compliance with the data validation requirements.

PR-AbO-08 In suitably equipped aircraft, WxS systems shall derive EDR.

PR-AbO-09 In suitably equipped aircraft, mean turbulence intensity (EDR) shall be calculated for each minute while the aircraft is operating.

PR-AbO-10 In suitably equipped aircraft, peak turbulence intensity (EDR) shall be calculated for each minute while the aircraft is operating.

PR-AbO-11 In suitably equipped aircraft, WxS systems shall comply with the EDR calculation requirements specified in AOSFRS Appendix C, Section C.1.2.1 and in the EDR Algorithm Overview section of the NCAR In Situ Vertical winds-based EDR Estimation Algorithm Description v0.9.

PR-AbO-12 In suitably equipped aircraft, WxS systems shall comply with the Water Vapor sensing and calculation requirements specified in AOSFRS Appendix C, Section C.2.

PR-AbO-13 When reporting Aircraft Configuration Indicator, WxS systems shall comply with the requirements specified in the Aircraft Configuration Indicator table.

PR-AbO-14 WxS observations shall be stored in a dedicated area of memory until transmitted.

PR-AbO-15 WxS systems shall report each of the parameters identified in the Header Data Block and Data Blocks 1 and 2 in Table 3-4 Aircraft-based Observation Parameter Specification Table.

PR-AbO-16 In suitably equipped aircraft, WxS systems shall report each of the parameters identified as Required if equipped in Data Block 2 in Table 3-4 Aircraft-based Observation Parameter Specification Table.

PRec-AbO-17 WxS systems should report each of the parameters identified in Data Block 3 in Table 3-4 Aircraft-based Observation Parameter Specification Table.

PRec-AbO-18 WxS systems may report each of the parameters identified in Data Block 4 in Table 3-4 Aircraft-based Observation Parameter Specification Table.


AbO Observation Compilation Requirements

PR-AbO-19 WxS systems shall either mask or not report invalid data.

PR-AbO-20 WxS systems shall compile observations continuously while the aircraft is operating.

PR-AbO-21 WxS systems shall compile observations that comprise the elements shown in Table 3-4 in compliance with the units, range, resolution, and reporting requirements noted.

PR-AbO-22 Input values for each measured datum shall be reported in the current observation.

PR-AbO-23 For each parameter in the observation, the Valid Parameter Indicator shall indicate whether valid data is contained in the observation.

PR-AbO-24 WxS systems shall mask invalid data within observations rather than reporting it

PR-AbO-25 When reporting wind values, WxS systems shall report a Roll Angle Flag that complies with the requirements specified in the Roll Angle Flag table.

PR-AbO-26 When reporting Water Vapor, WxS systems shall report the water content of the air in the native measurement units of the sensor or system used to measure or derive the parameter.

PR-AbO-27 Each WxS Observation Message shall include exactly one value for each parameter reported.

PR-AbO-28 WxS Messages shall be identified as such when transmitted.

PR-AbO-29 WxS Messages shall include a software version indicator.

PR-AbO-30 WxS Messages shall be compiled immediately prior to transmittal.


AbO Parameter SpecificationsData

Block

Reported

Parameter

Unit Range Resolu

tion

Reporting

Requirement

Header WxS MESSAGE

VERSION

Discrete NA NA Mandatory

Header VALID

PARAMETERS

INDICATOR

Binary NA NA Mandatory

Header UNIQUE

AIRCRAFT

IDENTIFIER


Header DATA

COMPRESSION

STATE


1 (Note

1)

LATITUDE Degrees,

Minutes,

Seconds

-90 to 90 (North

positive)

1

Second

Mandatory

1 (Note

1)

LONGITUDE Degrees,

Minutes,

Seconds

-180 to 180 (East

positive)

1

Second

Mandatory

1 (Note

1)

PRESSURE

ALTITUDE

Feet in

ICAO

standard

atmosphere

-1000 through

50000

10 Feet Mandatory

1 DATE DAY Day of

Month

0 through 31 1 Day Mandatory

1 TIME UTC

HH:MM:SS

0 through 23

hours: 0 through

59 minutes: 0

through 60

seconds

1

Second

Mandatory

2 STATIC AIR

PRESSURE

hPa (mbar) -1000 through

50000

1 hPa

(mbar)

Mandatory

2 STATIC AIR

TEMPERATURE

Degrees

Celsius

-99 through 99 0.1

Degree

Mandatory

2 WIND

DIRECTION

Degrees

True

0 through 359 1

Degree

Mandatory

2 WIND SPEED Knots 0 through 800 1 Knot Mandatory

2 ROLL ANGLE

FLAG

Discrete Per Roll Angle

Flag Table

NA Mandatory

Data

Block

Reported

Parameter

Unit Range Resolu

tion

Reporting

Requirement

2 MEAN EDR ε1/3 0 to 2 0.001 Required if

Equipped

2 PEAK EDR ε1/3 0 to 2 0.001 Required if

Equipped

2 WATER VAPOR Mixing ratio

kg/kg

0 to 38 g/kg 1x10-6

kg/kg

Required if

Equipped

2 WINDSHEAR

AIRSPEED

CHANGE

Knots -40 through 40 5 Knot Required if

Equipped

3 TRUE

AIRSPEED

Knots 0 through 800 1 Knot Recommend

ed

3 AIRCRAFT TYPE ICAO Type

or Emitter

Category

NA NA Recommend

ed

3 GROSS WEIGHT

(Note 2)

Pounds 0 through

1415000

40

Pounds

Recommend

ed

3 WINGSPAN Feet 0 to 400 1 Foot Recommend

ed

3 FLAP POSITION Degrees 0-50 1

Degree

Recommend

ed

3 A/C

CONFIGURATIO

N

Discrete Per Aircraft

Configuration

Indicator Table

NA Recommend

ed

3 TRUE HEADING Degrees 0 through 359.9 0.1

Degree

Recommend

ed

4 ICING STATUS

(Note 3)

Discrete NA NA Optional

4 DEPARTURE

AIRPORT

Character NA NA Optional

4 ARRIVAL

AIRPORT

Character NA NA Optional

4 GNSS

ALTITUDE

Feet -1000 through

50000

1 Foot Optional

4 ANTI-ICE Discrete NA NA Optional


WxS Message TypesWxS Message Description

Message Header Not a Message itself, but the elements that are part of all

Messages

Observation Message Message that contains a Header and exactly one observation.

Observation Messages are the same for Broadcast, Publish,

and Reply communications modes

Observation Subscription Message Message that contains a Header and an Observation

Subscription

Observation Request Message Message that contains a Header and an Observation Request

Configuration Request Message Message that contains a request for a Configuration Status

Message

Configuration Status Message Message that contains a Header and the configuration

settings for the WxS system

Optimization Message Message that contains a Header and the parameters

DEPARTURE STATION and DESTINATION STATION


WxS Observation Message Reception Rates

WxS Observation Message reception rates are based on the goal of characterizing the atmosphere in terms of its air mass movements, stability, density, and humidity, in support of existing and proposed services that rely on aircraft observations.

A 60-second, low-rate reception period is associated with characterizing the atmosphere through continuous reception of AbO parameters. • Continuous updating of AbO parameters argues in favor of

Broadcast mode or Publish-Subscribe mode communications.

Certain applications require AbO parameters to be reported at higher rates. For such applications, a 10-second, high-rate reception period is provided on the basis that the high rate reception requirements would be of limited duration.• Publish-Subscribe mode or Request-Reply mode

communications could satisfy such requirements.


WxS Transmittal Requirements and

RecommendationsPR-AbO-31 WxS systems shall use a time-based observation reporting scheme.

PR-AbO-32 WxS systems shall report observations beginning with the OUT event.

PR-AbO-33 WxS systems shall cease reporting observations following transmittal of the observation closest to the IN event.

PR-AbO-34 WxS observations shall be reported in all phases of flight, including taxi, takeoff, ascent, level flight, descent, and landing.

PR-AbO-35 WxS systems shall transmit observations in compliance with subscription requirements.

PR-AbO-36 WxS systems shall transmit observations in compliance with request requirements.

PR-AbO-37 Transmission of WxS observations shall be made so as to ensure a 95% probability of reception of an observation, within the effective range of the transmitter, within the required reception period for the operating mode.

PR-AbO-38 WxS systems shall be able to satisfy Publication or Reply mode communications requirements while simultaneously satisfying Broadcast mode communications requirements.

PR-AbO-39 WxS systems shall discard observations after they are transmitted.

PR-AbO-40 WxS Messages shall be transmitted with error detection provisions.

PRec-AbO-41 Addressed WxS Messages may be transmitted with error correction provisions.

PRec-AbO-42 WxS systems should be capable of transmitting a WxS Optimization Message.

PRec-AbO-43 WxS systems should be capable of transmitting a WxS Status Message.

PR-AbO-44 If enabled, WxS Configuration Messages shall be requested by data link transmittal of a WxS Configuration Request Message.

PRec-AbO-45 A WxS optimization message may be sent to the National Meteorological and Hydrological Service and/or airline prior to departure of every flight.

PRec-AbO-46 Data compression may be used to reduce message size.


WxS Configuration Control Requirements

and RecommendationsPR-AbO-47 WxS systems shall be default configured to operate in Low Rate Broadcast mode.

PR-AbO-48 WxS systems shall be configurable to operate temporarily in Low Rate Publication, High Rate Publication or High Rate Reply modes through receipt of a Subscription or Request message.

PR-AbO-49 WxS systems shall return to their default configuration if reconfiguration fails or is lost.

PR-AbO-50 WxS systems shall be able to be turned off for the duration of the current flight, for up to 99 flights, or until turned back on, after which the configuration will revert to the default configuration.

PR-AbO-51 If the WxS system is turned back on after being switched off for the duration of the current flight, for up to 99 flights, or until turned back on, it shall return to nominal operation within one low rate reception period after startup is complete.

PRec-AbO-52 WxS systems should be configurable to enable or disable reporting in a minimum of 10 geographical boxes defined by two latitude/longitude coordinate pairs. Outside these boxes reporting is enabled or disabled depending on the airport limitation status.

PRec-AbO-53 WxS systems should be configurable to enable or disable reporting around a minimum of 20 and up to 50 airports. The settings applied to these specific locations shall take priority over the geographical limiting function.

PRec-AbO-54 It should be possible to configure a single time window during which reporting is inhibited. This setting shall have priority over all other settings except turning off reporting.

PRec-AbO-55 WxS systems should provide a means to obtain the current configuration from the system through a Configuration Request Message.


Discussion


Introduction to RTCA Special Committee 206 and Standards ......Update the MASPS 6 presents comments...

Documents

Transcript of Introduction to RTCA Special Committee 206 and Standards ......Update the MASPS 6 presents comments...